Pointing device for interacting with touch-sensitive devices and method thereof

ABSTRACT

The present application is directed to a pointing device and a method for interacting with touch-sensitive devices. The pointing device includes a supporting member, first and second contact points fixed on the supporting member and adapted to be in contact with a touch-sensitive layer in a default state, and at least one movable contact point mounted on the supporting member and movable from the default state to a fully depressed state adjacent to the second contact point to form a combined touch area on the touch-sensitive layer having an offset center that is offset from a center of the second contact point so that the second touch point is shifted to an offset position in alignment with the offset center.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation of patent application Ser. No.14/810,454 filed on Jul. 27, 2015, which is a continuation-in-part ofpatent application Ser. No. 14/284,379 filed on May 21, 2014, whichclaims the benefit of Hong Kong Short-term Patent Application No.13106809.3 filed on Jun. 7, 2013; the contents of which are herebyincorporated by reference.

FIELD OF INVENTION

The present application refers to a pointing device to be used on touchscreens, more particularly, to a pointing device and a method forinteracting with touch-sensitive devices.

BACKGROUND OF INVENTION

Touch-sensitive devices are gaining tremendous popularity in today'sconsumer electronics market. Such devices are playing important roles inpeople's daily lives. In the past, pointing devices such as mice andtrackballs are commonly used for navigating on the user interface ofcomputers. The buttons of these traditional pointing devices onlyacknowledge on/off input from the user and are incorporated with complexmechanical/electronic constructions which incurred substantial costs inmanufacturing. Moreover, these pointing devices require the user tolearn and to get used with the controls through some period of practice.All in all, these pointing devices fail to provide an intuitive way forthe user to interact with electronic devices. The present applicationprovides a pointing device to be used on most touch-sensitive devicessuch as the Apple iPad® which mitigates the inconsistencies andinaccuracies caused by using bare fingers on touch-sensitive devices andallows the control of a range of values by varying the pressure by theuser. Further, the present application provides an intuitive way for theuser to interact with the touch-sensitive devices.

SUMMARY OF INVENTION

According to one aspect, there is provided a pointing device forinteracting with a touch-sensitive device including a supporting member,a first contact point fixed on the supporting member and adapted to bein contact with a touch-sensitive layer and generate a first touch pointon a screen underneath the touch-sensitive layer, a second contact pointfixed on the supporting member and spaced laterally apart from the firstcontact point and adapted to be in contact with the touch-sensitivelayer and generate a second touch point on the screen, and a thirdcontact point mounted on the supporting member and movable by a firstactuating assembly from a default state where only the first and secondcontact points are in contact with the touch-sensitive layer to itsfully depressed state where the third contact point is also in contactwith the touch-sensitive layer adjacent to the second contact point.

When the first, second and third contact points are in contact with thetouch-sensitive layer, the second and third contact points arerecognized as one contact point and produce a first combined touch areaon the touch-sensitive layer having a first offset centre that is offsetfrom a centre of a touch area on the touch-sensitive layer of the secondcontact point so that the second touch point is shifted to a firstoffset position in alignment with the first offset centre.

In one embodiment, the first actuating assembly may include a firstactuating member provided on a first raised platform of the supportingmember, and having an upper end provided with a first actuating buttonand a lower end coupled with the third contact point disposed below thefirst raised platform; and a first biasing member mounted on the firstactuating member and held between the first actuating button and thefirst raised platform for biasing the third contact point underneath thefirst raised platform. When a force is exerted on the first actuatingbutton against biasing force of the first biasing member, the thirdcontact point moves to its fully pressed state.

In one embodiment, the first actuating member may be a first shaftpassing through a first opening formed on the first raised platform, andthe first biasing member can be a coil spring.

The pointing device may further include a fourth contact point mountedon the supporting member and movable by a second actuating assembly fromthe default state where only the first and second contact points are incontact with the touch-sensitive layer to its fully depressed statewhere the fourth contact point is also in contact with thetouch-sensitive layer adjacent to the second contact point. When thefirst, second and fourth contact points are in contact with thetouch-sensitive layer, the second and fourth contact points arerecognized as one contact point and produce a second combined touch areaon the touch-sensitive layer having a second offset centre that isoffset from the centre of the touch area of the second contact point sothat the second touch point is shifted to a second offset position inalignment with the second offset centre. When the first, second, thirdand fourth contact points are in contact with the touch-sensitive layer,the second, third and fourth contact points are recognized as onecontact point and produce a third combined touch area on thetouch-sensitive layer having a third offset centre that is offset fromthe centre of the touch area of the second contact point so that thesecond touch point is shifted to a third offset position in alignmentwith the third offset centre.

In one embodiment, the second actuating assembly may include a secondactuating member provided on a second raised platform of the supportingmember, and having an upper end provided with a second actuating buttonand a lower end coupled with the fourth contact point disposed below thesecond raised platform; and a second biasing member mounted on thesecond actuating member and held between the second actuating button andthe second raised platform for biasing the fourth contact pointunderneath the second raised platform. When a force is exerted on thesecond actuating button against biasing force of the second biasingmember, the fourth contact point moves to its fully pressed state.

In one embodiment, the second actuating member may include a secondshaft passing through a second opening formed on the second raisedplatform, and the second biasing member can be a coil spring.

In one embodiment, a plurality of changes in displacement of the secondtouch point relative to the first touch point may define a variety ofpatterns of movements which are detected and recognized by thetouch-sensitive device.

In one embodiment, data values of a list of the patterns can be storedin a data file which is accessible by executable applications on thetouch-sensitive device.

The pointing device may further include at least one additional contactpoint mounted on the supporting member and movable by at least oneadditional actuating assembly from the default state where only thefirst and second contact points are in contact with the touch-sensitivelayer to its fully depressed state where the at least one additionalcontact point is also in contact with the touch-sensitive layer adjacentto the second contact point.

According to another aspect, there is provided a method for interactingwith the touch-sensitive device using the pointing device mentionedabove. The method may include the step of placing the pointing device onthe screen at the default state where only the first and second contactpoints are in contact with the touch-sensitive layer to thereby generatethe first and second touch points on the screen respectively.

In one embodiment, the method may include the step of pressing the firstactuating assembly so that the third contact point is in contact withthe touch-sensitive layer to thereby shift the second touch point to thefirst offset position.

According to yet another aspect, there is provided a method forinteracting with the touch-sensitive device using the pointing devicementioned above. The method may include the step of placing the pointingdevice on the screen at the default state where only the first andsecond contact points are in contact with the touch-sensitive layer tothereby generate the first and second touch points on the screenrespectively.

The method may further include the step of pressing the first actuatingassembly so that the third contact point is in contact with thetouch-sensitive layer to thereby shift the second touch point to thefirst offset position.

The method may further include the step of pressing the second actuatingassembly so that the fourth contact point is in contact with thetouch-sensitive layer to thereby shift the second touch point to thesecond offset position.

The method may further include the step of pressing the first and secondactuating assemblies simultaneously so that the third and fourth contactpoints are in contact with the touch-sensitive layer respectively tothereby shift the second touch point to the third offset position.

The method may further include the steps of (i) pressing the firstactuating assembly so that the third contact point is in contact withthe touch-sensitive layer to thereby shift the second touch point to thefirst offset position; and then (ii) pressing the second actuatingassembly so that the fourth contact point is in contact with thetouch-sensitive layer to thereby shift the second touch point from thefirst offset position to the third offset position.

The method may further include the steps of (i) pressing the secondactuating assembly so that the fourth contact point is in contact withthe touch-sensitive layer to thereby shift the second touch point to thesecond offset position; and then (ii) pressing the first actuatingassembly so that the third contact point is in contact with thetouch-sensitive layer to thereby shift the second touch point from thesecond offset position to the third offset position.

The method may further include the steps of determining and recordingpositions of the first and second touch points, determining a change indisplacement of the second touch point, determining a distance betweenthe first and second touch points, comparing a value of the distancewith a list of preset values stored in a data file, and triggering acommand if the value of the distance matches a preset value.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1a shows an exploded sectional view of the pointing device of anembodiment of the present application;

FIG. 1b shows a bottom view of the pointing device of an embodiment ofthe present application in its default state;

FIG. 1c shows a bottom view of the pointing device of an embodiment ofthe present application with the housing is fully depressed;

FIG. 1d shows a side view of the pointing device of an embodiment of thepresent application in its default state;

FIG. 1e shows a side view of the pointing device of an embodiment of thepresent application with the housing is fully depressed;

FIG. 2a-2f show examples of embodiment of the present application withdifferent patterns of movement of contact points;

FIG. 3 shows an example of three pointing devices of different patternsbeing used on a touch-sensitive device;

FIG. 4a shows the touch points detected on the screen by thetouch-sensitive device where the pointing device is in its defaultstate;

FIG. 4b shows the touch points detected on the screen by thetouch-sensitive device where the pointing device's housing is fullydepressed;

FIG. 5 shows the change of pointing direction of the device;

FIGS. 6a and 6b show an elevation view and a cutaway view of thepointing device and the default positions of the contact points beforethe housing is pressed down;

FIGS. 7a and 7b show an elevation view and a cutaway view of thepointing device and the positions of the contact points when the housingis pressed down by a user;

FIG. 8a shows a sectional view of the pointing device of anotherembodiment of the present application in its default state;

FIG. 8b shows a sectional view of the pointing device of the embodimentof FIG. 8a when the actuating member is pressed down by a user;

FIG. 9a shows a sectional view of the pointing device with more than oneactuating member of another embodiment of the present application in itsdefault state;

FIGS. 9b-9c show sectional views of the pointing device with more thanone actuating member of the embodiment of FIG. 9a when one of theactuating members is pressed down by a user; and

FIGS. 10a-10b show the touch points detected on the screen by thetouch-sensitive device when all actuating members are pressed down by auser.

DETAILED DESCRIPTION

The present application refers to a pointing device for interacting withtouch-sensitive devices and a method for interacting withtouch-sensitive devices.

The pointing device may be used for navigating on a touch-sensitivedevice, or as a component of an entertaining system used withtouch-sensitive devices. The pointing device provides up to four typesof inputs to the touch-sensitive device, namely, (1) positioning of thedevice with reference to the screen coordinates; (2) pointing directionof the device; (3) a command actuated by depressing the housing; (4) acontinuous range of values when the button is being gradually depressed.

Identification of the pointing device is based on the patterns and thedisplacements of touch points before-and-after the housing is fullypressed by the user. The structure and components of the pointing devicewill be discussed in the following.

An exploded view of the device 100 is shown in FIG. 1a . A housing 101houses all the components and covers a portion of a base 105. The base105 may be non-conductive. An opening is formed on the bottom of thehousing 101 to receive the base 105. The base 105 is formed in a way sothat it is coupled with the opening of housing 101 while a portion ofthe base 105 is inserted into the housing 101.

As shown in FIGS. 1b and 1c , a plurality of apertures is provided onthe base 105 in accordance with the designated pattern associated with aparticular pointing device. A sliding member 102 and a supporting member104 are provided with contact points 106 and 107 respectively. Thecontact points 106 and 107 are inserted into and through the aperturesprovided on the base 105 such that the contact points can be in contactwith the surface of the screen of a touch-sensitive device during use.It is appreciated that first contact point 106 is provided on thesliding member 102 and second contact point 107 is provided on thesupporting member 104. Moreover, a protruded peripheral edge 108 isprovided on the base 105. The contact points 106 and 107 protrudedownwardly and are substantially flush (i.e. at the same height) withthe bottom of the protruded peripheral edge 108 in order to be incontact with the screen during use.

In FIG. 1a , an actuating member 109 is provided in the housing 101 andhas a slanted surface 1091 for engaging with the sliding member 102. Thesliding member 102 is provided with a corresponding slanted surface1021. A biasing member 103 in form of a helical spring, as anon-limiting example, is situated between the sliding member 102 and thesupporting member 104. FIG. 1a shows an unassembled view of the pointingdevice 100 indicating the arrangement of the above-mentioned components.As a downward pressure is applied on the housing 101 by the user,actuating member 109 pushes downward and the slanted surface 1091 forcesthe sliding member 102 to move in the direction as shown in FIGS. 1b-1c. The supporting member 104 is fixedly mounted on the base 105 andcauses the biasing member 103 in between to be compressed. Once the userreleases the pressure on the housing 101, the biasing member 103decompresses and pushes the sliding member 102 back to its defaultposition. Further, the slanted surface 1021 of the sliding member 102forces the housing 101 to rise to its default position. As the slidingmember 102 moves, the first contact point 106 displaces relative to thesecond contact point 107 which is formed with the supporting member 104.FIG. 1d and FIG. 1e illustrate the device 100 when pressure is applied.

When the pointing device 100 is placed on a screen of a touch-sensitivedevice and pressure is applied on the housing 101, i.e., the housing isbeing fully pressed downward, the contact points 106, 107 are pressedagainst and in contact with the surface of the screen and causes firstcontact point 106 to slide relative to second contact point 107. Thesliding movement of first contact point 106 relative to second contactpoint 107 forms a pattern which is detected and recognized by thetouch-sensitive device. Once the movement pattern is detected by thetouch-sensitive device, subsequent actions may be executed to indicatethe system acknowledged the input, for a non-limiting example, an imagecorresponds to that particular device 100 may be displayed on the screen21 as shown in FIG. 3. It is appreciated that data values of a list ofpatterns are stored in the data file which is accessible by executableapplications on the touch-sensitive device 20.

FIGS. 2a-2f show a variety of patterns of movements of the first contactpoint 106 relative to second contact point 107. These unique patternsare individually recognized by the touch-sensitive device according tothe data values in a predetermined list of patterns as mentioned.Details of how the patterns are interpreted by the touch-sensitivedevice will be discussed in the following.

Reference is made to FIG. 4a . For a non-limiting example, the twocontact points 106 and 107 of the pointing device 100 are in contactwith the screen 21, positions in terms of X and Y coordinates of the twotouch points 200 a and 200 b on the screen 21 are detected andregistered by the touch-sensitive device 20.

When housing 101 is depressed, the movable first contact point 106slides to a direction relative to second contact point 107. In theexample, first contact point 106 moves closer to second contact point107 in a horizontal direction as shown in FIG. 4b . It is appreciatedthat the touch points 200 a and 200 b correspond to the movements ofcontact points 106 and 107. FIGS. 6a and 6b show an elevation view and acutaway view of the device and the default positions of the contactpoints 106 and 107 before the housing 101 is pressed down, while FIGS.7a and 7b show an elevation view and a cutaway view of the device andthe positions of the contact points 106 and 107 when the housing 101 ispressed down by a user. An image example 32 is displayed on the screen21 indicating the pointing device 100 is identified by thetouch-sensitive device based on the list of patterns stored in the datafile.

Referring to FIG. 5, assume the movable contact point is beingrecognized and the corresponding finger IDs are matched and recorded.Regardless of the state of the pointing device, the pointing directionof the device is determined by vector s generated by the currentpositions of the two contact points with reference to vector r generatedby the last recorded positions of the two contact points. The degree ofrotation of the pointing device depends on angle θ in-between vector rand vector s. For example, if there is an image attached with theposition of the device, the orientation changes depending on angle θin-between vector r and vector s, indicating the change of pointingdirection of the device.

The two individual touch points 200 a and 200 b are differentiated bythe absolute delta change in displacement of each touch point withreference to its previous position recorded, i.e., before any change ofdisplacement takes place.

Let x1, y1 and x2, y2 be the x and y coordinates of touch points 200 aand 200 b of their previous positions respectively (the housing is notpressed down), and let x1′, y1′ and x2′, y2′ be the x and y coordinatesof touch points 200 a and 200 b of their current positions respectively(the housing is fully pressed down). Accordingly, the absolute change indisplacement of touch point 200 a, ΔD1, may be determined by:ΔD ₁=√{square root over (|(x ₁ ′−x ₁)²+(y ₁ ′−y ₁)²|)}

While the absolute change in displacement of touch point 200 b, ΔD2, maybe determined by:ΔD ₂√{square root over (|(x ₂ ′−x ₂)²+(y ₂ ′−y ₂)²|)}

As second contact point 107 (touch point 200 b) in the above example isa fixed contact point, ΔD2 is theoretically 0.

The value of ΔD1 reflects the pressure act on the housing 101 on thescreen 21. The more pressure is act on the housing, the farther thesliding member 102 travels and higher the value of ΔD1 is resulted. Thechange of the pressure level acting on the housing 101 is transformed tonumerical values for controlling a range of values on thetouch-sensitive device. For examples, the change of the pressure levelmay be used for controlling sliders or scrolling pages.

In order for the touch-sensitive device to identify and distinguish aspecific pointing device, the direct distance between the touch pointsis determined. L signifies the initial direct distance between the twotouch points, i.e., 200 a and 200 b, and L′ represents the directdistance between 200 a and 200 b after the housing 101 is fullydepressed.

The values L and L′ are then stored in the memory of the touch-sensitivedevice and routines are executed to compare these values with the presetvalues of L_(max) and L_(min) in the list of patterns in a data file.L_(max) is the variable of the maximum allowed distance between the twotouch points, and L_(min) is the variable of the minimum alloweddistance between the two touch points. The values of L_(max) and L_(min)of each pattern are unique and are accessible by executableapplications. Upon comparison of these values and a match is found, aspecific command may be executed. For a non-limiting example, acorresponding image of the particular device will be displayed toacknowledge the identification of the device as shown in FIG. 3.

Both L and L′ allow maximum absolute error S by default 0.1 cm but notlimited to this value.

To be validated, both L and L′ must also satisfy the following equation:|L _(measured) −L _(data) |≦S

L_(measured) represents either L or L′. L_(data) represents eitherL_(max) or L_(min).

The above-mentioned pointing device and method of the presentapplication utilize at least one movable touch point rather than twofixed touch points so that a L_(max) and L_(min) between the two touchpoints may be determined to serve the purpose of increasing the matchingrequirement of the recorded values with the preset values in the datafile. Assuming only two fixed touch points are used, the recognition ofpatterns would merely base on the distance L between the two touchpoints. As a result, a user may easily imitate the touch point patternby placing fingers on the screen. This is of particular significancewhen the pointing device is to be used in games and applications wherethe strict use of the device is essential.

The pointing device and method of the present application allow thedetermination of the position and orientation of the device on atouch-sensitive device with least number of touch points required. Thesame also allow interactive inputs by the user such as clicking, doubleclicking, sliding and scrolling, dragging and dropping of objectsdisplayed on the screen of the touch-sensitive device. Furthermore, itis another advantage of the present application that multi-touchgestures can be simulated for interacting with designated applicationson the touch-sensitive devices.

Apart from allowing the sliding member 102 with contact point 106 tomove across the screen by adding pressure on housing 101, such actioncan be simulated by replacing the housing 101, actuating member 109,sliding member 102, and biasing member 103; and (2) extending thesupporting member 104, as described below according to anotherembodiment of the pointing device shown in FIGS. 8-10 with likereference numerals represent like parts.

As shown in FIG. 8a , the pointing device 100 may include first, secondand third contact points 107, 1041, 2012 mounted on a supporting member104. As used herein, the terms “first”, “second” and “third” etc. arenot used to show a serial or numerical limitation but instead are usedto distinguish or identify the various members of the device. The firstcontact point 107 may be fixed on the supporting member 104 and adaptedto be in contact with a touch-sensitive layer 22 and generate a firsttouch point 200 a on a screen 21 underneath the touch-sensitive layer22. The second contact point 1041 may be fixed on the supporting member104 and spaced laterally apart from the first contact point 107 andadapted to be in contact with the touch-sensitive layer 22 and generatea second touch point 200 b on the screen 21. The third contact point2012 may be mounted on the supporting member 104 and movable by a firstactuating assembly 201 from a default state where only the first andsecond contact points 107, 1041 are in contact with the touch-sensitivelayer 22 to its fully depressed state where the third contact point 2012is also in contact with the touch-sensitive layer 22 adjacent to thesecond contact point 1041, as shown in FIG. 8 b.

When the first, second and third contact points 107, 1041, 2012 are incontact with the touch-sensitive layer 22, the second and third contactpoints 1041, 2012 can be recognized as one contact point and produce afirst combined touch area A′ on the touch-sensitive layer 22 having afirst offset centre Ctr′ that is offset from the centre Ctr of a toucharea A on the touch-sensitive layer 22 of the second contact point 1041so that the second touch point 200 b is shifted to a first offsetposition in alignment with the first offset centre Ctr′.

The first actuating assembly 201 may include a first actuating shaft2013 passing through a first opening 2014 formed on a first raisedplatform 2015 of the supporting member 104. The first actuating shaft2013 may have an upper end provided with a first actuating button 2016and a lower end coupled with the third contact point 2012 disposed belowthe first raised platform 2015. The first actuating assembly 201 mayalso include a first biasing member such as a coil spring 2011 mountedon the first actuating shaft 2013 and held between the first actuatingbutton 2016 and the first raised platform 2015 for biasing the thirdcontact point 2012 underneath the first raised platform 2015. When aforce is exerted on the first actuating button 2016 against biasingforce of the first biasing member 2011, the third contact point 2012moves to its fully pressed state, as shown in FIG. 8 b.

In FIG. 8b , by pressing down the actuating assembly 201 towards thescreen 21, the three contact points 107, 1041 and 2012 touch thetouch-sensitive layer 22. This third contact point 2012 will combinewith the contact point 1041 as one contact point and inherit the fingerID of the contact point 1041. Since the distance between two contactpoints 1041 and 2012 is short, the touch action will be recognized as anextension of the touch area A of the same finger or contact pointinstead of an additional contact point. As a result, the touch point 200b will be gradually and steadily moving towards the designated offsetposition which is the centre Ctr′ of touch area A′. This can ensureprecise touch position and moving displacement every time the actuatingassembly 201 is pressed. Once the user releases the pressure on theactuating assembly 201, the biasing member 2011 decompresses and pushesthe actuating assembly 201 back to its default position. The touch point200 b will also be gradually and steadily moving back to its originalposition, which is the position of contact point 1041.

To allow more moving directions and moving displacements using the samepointing device 100, one or more actuating assemblies 201 can be addedto the pointing device. FIGS. 9a-9c show that the pointing device 100may be provided with two actuating assemblies 201 and 202. The structureof the second actuating assembly 202 may be the same as that of thefirst actuating assembly 201. In FIG. 9a , the pointing device 100 is inits default state with two contact points 107 and 1041 touching thetouch-sensitive layer 22. As shown in FIG. 9b , when the first actuatingassembly 201 is pressed towards the screen 21, touch point 200 b shiftstowards the position of contact point 2012. As shown in FIG. 9c , whenthe second actuating assembly 202 is pressed towards the screen 21,touch point 200 b shifts towards the position of a fourth contact point2022.

The fourth contact point 2022 may be mounted on the supporting member104 and movable by the second actuating assembly 202 from the defaultstate where only the first and second contact points 107, 1041 are incontact with the touch-sensitive layer 22 to its fully depressed statewhere the fourth contact point 2022 is also in contact with thetouch-sensitive layer 22 adjacent to the second contact point 1041.

When the first, second and fourth contact points 107, 1041, 2022 are incontact with the touch-sensitive layer 22, the second and fourth contactpoints 1041, 2022 can be recognized as one contact point and produce asecond combined touch area A″ on the touch-sensitive layer 22 having asecond offset centre Ctr″ that is offset from the centre Ctr of thetouch area A of the second contact point 1041 so that the second touchpoint 200 b is shifted to a second offset position in alignment with thesecond offset centre Ctr″.

FIGS. 10a and 10b show a plurality of arrangement of contact points 2012and 2022 in relation to the positions of contact points 107 and 1041.When the first, second, third and fourth contact points 107, 1041, 2012,2022 are in contact with the touch-sensitive layer 22, the second, thirdand fourth contact points 1041, 2012, 2022 can be recognized as onecontact point and produce a third combined touch area A′″ on thetouch-sensitive layer 22 having a third offset centre Ctr′″ that isoffset from the centre Ctr of the touch area A of the second contactpoint 1041 so that the second touch point 200 b is shifted to a thirdoffset position in alignment with the third offset centre Ctr′″, asshown by the arrows in FIGS. 10a and 10 b.

The four contact points 107, 1041, 2012, 2022 are not necessary to bealigned in a straight line and may be arranged in any possiblepositions. When all contact points 107, 1041, 2012, 2022 are touchingthe touch sensitive layer 22, the three contact points 1041, 2012 and2022 will be recognized as one contact point with a larger touch areaA′″ and its designated offset position will be the centre Ctr′″ of thetouch area A′″.

Each actuating assembly 201, 202 can be pressed solely, or in differentorders, or simultaneously to form a variety of commands and data input.

When the pointing device 100 is placed on the screen at the defaultstate where only the first and second contact points 107, 1041 are incontact with the touch-sensitive layer 22, the first and second touchpoints 200 a, 200 b will be generated on the screen 21 respectively.

When a user presses only the first actuating assembly 201, the thirdcontact point 2012 will be in contact with the touch-sensitive layer 22and the second touch point 200 b will be shifted to the first offsetposition. Also, when a user presses only the second actuating assembly202, the fourth contact point 2022 will be in contact with thetouch-sensitive layer 22 and the second touch point 200 b will beshifted to the second offset position.

When a user presses the first and second actuating assemblies 201, 202simultaneously, the third and fourth contact points 2012, 2022 will bein contact with the touch-sensitive layer 22 respectively, and thesecond touch point 200 b will be shifted to the third offset position.

Furthermore, the user may (i) press the first actuating assembly 201first so that the third contact point 2012 is in contact with thetouch-sensitive layer 22 to thereby shift the second touch point 200 bto the first offset position; and then (ii) press the second actuatingassembly 202 so that the fourth contact point 2022 is also in contactwith the touch-sensitive layer 22 to thereby shift the second touchpoint 200 b from the first offset position to the third offset position.

In another way, the user may (i) press the second actuating assembly 202first so that the fourth contact point 2022 is in contact with thetouch-sensitive layer 22 to thereby shift the second touch point 200 bto the second offset position; and then (ii) press the first actuatingassembly 201 so that the third contact point 2012 is also in contactwith the touch-sensitive layer 22 to thereby shift the second touchpoint 200 b from the second offset position to the third offsetposition.

The method may further include the steps of determining and recordingpositions of the first and second touch points, determining a change indisplacement of the second touch point, determining a distance betweenthe first and second touch points, comparing a value of the distancewith a list of preset values stored in a data file, and triggering acommand if the value of the distance matches a preset value. Details ofthese further steps have been described in the previous embodiment.

Although it has been shown and described that there are two movablecontact points 2012, 2022, it is understood by one skilled in the artthat there can be three or more movable contact points provided on thepointing device. Similarly, three or more movable contact points canform different combined touch areas having different offset centersbased on the order of corresponding actuating assemblies being fullydepressed. They can be pressed solely, or in different orders, ortogether with other actuating members simultaneously to form a varietyof commands and data input.

The touch-sensitive device can be an iPad, an iPhone, or any Androidequipped touch-sensitive devices, or any touch-sensitive devicesequipped with other operating systems. It is contemplated that thepointing device disclosed in the present application can be compatiblewith all kinds of touch-sensitive devices, regardless of screen sizes oroperating systems.

It may be appreciated that various modifications and additions can bemade to the exemplary embodiments discussed without departing from thescope of the present invention. For example, while the embodimentsdescribed above refer to particular features, the scope of thisinvention also includes embodiments having different combinations offeatures and embodiments that do not include all of the above describedfeatures.

What is claimed is:
 1. A pointing device for interacting with atouch-sensitive device comprising: a supporting member; a first contactpoint fixed on the supporting member and adapted to be in contact with atouch-sensitive layer and generate a first touch point on a screenunderneath the touch-sensitive layer; a second contact point fixed onthe supporting member and spaced laterally apart from the first contactpoint and adapted to be in contact with the touch-sensitive layer andgenerate a second touch point on the screen; a third contact pointmounted on the supporting member and movable by a first actuatingassembly from a default state where only the first and second contactpoints are in contact with the touch-sensitive layer to its fullydepressed state where the third contact point is also in contact withthe touch-sensitive layer adjacent to the second contact point; and afourth contact point mounted on the supporting member and movable by asecond actuating assembly from the default state where only the firstand second contact points are in contact with the touch-sensitive layerto its fully depressed state where the fourth contact point is also incontact with the touch-sensitive layer adjacent to the second contactpoint.
 2. The pointing device as claimed in claim 1, wherein the firstactuating assembly comprises: a first actuating member provided on afirst raised platform of the supporting member, and having an upper endprovided with a first actuating button and a lower end coupled with thethird contact point disposed below the first raised platform; and afirst biasing member mounted on the first actuating member and heldbetween the first actuating button and the first raised platform forbiasing the third contact point underneath the first raised platform;whereby when a force is exerted on the first actuating button againstbiasing force of the first biasing member, the third contact point movesto its fully pressed state.
 3. The pointing device as claimed in claim2, wherein the first actuating member comprises a first shaft passingthrough a first opening formed on the first raised platform.
 4. Thepointing device as claimed in claim 2, wherein the first biasing memberis a coil spring.
 5. The pointing device as claimed in claim 1, whereinthe second actuating assembly comprises: a second actuating memberprovided on a second raised platform of the supporting member, andhaving an upper end provided with a second actuating button and a lowerend coupled with the fourth contact point disposed below the secondraised platform; and a second biasing member mounted on the secondactuating member and held between the second actuating button and thesecond raised platform for biasing the fourth contact point underneaththe second raised platform; whereby when a force is exerted on thesecond actuating button against biasing force of the second biasingmember, the fourth contact point moves to its fully pressed state. 6.The pointing device as claimed in claim 5, wherein the second actuatingmember comprises a second shaft passing through a second opening formedon the second raised platform.
 7. The pointing device as claimed inclaim 5, wherein the second biasing member is a coil spring.
 8. Thepointing device as claimed in claim 1, wherein a plurality of changes indisplacement of the second touch point relative to the first touch pointdefines a variety of patterns of movements which are detected andrecognized by the touch-sensitive device.
 9. The pointing device asclaimed in claim 1, further comprising at least one additional contactpoint mounted on the supporting member and movable by at least oneadditional actuating assembly from the default state where only thefirst and second contact points are in contact with the touch-sensitivelayer to its fully depressed state where the at least one additionalcontact point is also in contact with the touch-sensitive layer adjacentto the second contact point.
 10. The pointing device as claimed in claim1, wherein when the first, second and third contact points are incontact with the touch-sensitive layer, the second and third contactpoints are recognized as one contact point and produce a first combinedtouch area on the touch-sensitive layer having a first offset centrethat is offset from a centre of a touch area on the touch-sensitivelayer of the second contact point so that the second touch point isshifted to a first offset position in alignment with the first offsetcentre.
 11. The pointing device as claimed in claim 10, wherein when thefirst, second and fourth contact points are in contact with thetouch-sensitive layer, the second and fourth contact points arerecognized as one contact point and produce a second combined touch areaon the touch-sensitive layer having a second offset centre that isoffset from the centre of the touch area of the second contact point sothat the second touch point is shifted to a second offset position inalignment with the second offset centre.
 12. A method for interactingwith the touch-sensitive device using the pointing device of claim 10,comprising the step of placing the pointing device on the screen at thedefault state where only the first and second contact points are incontact with the touch-sensitive layer to thereby generate the first andsecond touch points on the screen respectively.
 13. The method asclaimed in claim 12, comprising the step of pressing the first actuatingassembly so that the third contact point is in contact with thetouch-sensitive layer to thereby shift the second touch point to thefirst offset position.
 14. The method as claimed in claim 12, furthercomprising the steps of determining and recording positions of the firstand second touch points, determining a change in displacement of thesecond touch point, determining a distance between the first and secondtouch points, comparing a value of the distance with a list of presetvalues stored in a data file, and triggering a command if the value ofthe distance matches a preset value.
 15. A method for interacting withthe touch-sensitive device using the pointing device of claim 11,wherein when the first, second, third and fourth contact points are incontact with the touch-sensitive layer, the second, third and fourthcontact points are recognized as one contact point and produce a thirdcombined touch area on the touch-sensitive layer having a third offsetcentre that is offset from the centre of the touch area of the secondcontact point so that the second touch point is shifted to a thirdoffset position in alignment with the third offset centre; and whereinthe method comprises the step of placing the pointing device on thescreen at the default state where only the first and second contactpoints are in contact with the touch-sensitive layer to thereby generatethe first and second touch points on the screen respectively.
 16. Themethod as claimed in claim 15, further comprising the step of pressingthe second actuating assembly so that the fourth contact point is incontact with the touch-sensitive layer to thereby shift the second touchpoint to the second offset position.
 17. The method as claimed in claim15, further comprising the step of pressing the first and secondactuating assemblies simultaneously so that the third and fourth contactpoints are in contact with the touch-sensitive layer respectively tothereby shift the second touch point to the third offset position. 18.The method as claimed in claim 15, further comprising the steps of (i)pressing the first actuating assembly so that the third contact point isin contact with the touch-sensitive layer to thereby shift the secondtouch point to the first offset position; and then (ii) pressing thesecond actuating assembly so that the fourth contact point is in contactwith the touch-sensitive layer to thereby shift the second touch pointfrom the first offset position to the third offset position.
 19. Themethod as claimed in claim 15, further comprising the steps of (i)pressing the second actuating assembly so that the fourth contact pointis in contact with the touch-sensitive layer to thereby shift the secondtouch point to the second offset position; and then (ii) pressing thefirst actuating assembly so that the third contact point is in contactwith the touch-sensitive layer to thereby shift the second touch pointfrom the second offset position to the third offset position.